Forming of paperboards



Feb. 8, 1938. E. R. SMITH FORMING OF PAPERBOARDS Filed Aug. 19, 1935 Patented Feb. 8, 1938 PATENT OFFICE FORMING 0F PAPERBOARDS Ewen Ross Smith, London, England, assigner to `Papercrete Limited, London, England Application August 19, 1935, Serial No. 36,925 In Great Britain August 20, 1934 3 Claims.

This invention relates to the forming of paper boards or plates of relatively considerable thickness and has for its object to devise a simple and efcient method and apparatus by which such boards may be readily and cheaply made of any desired thickness.

The invention consists in a method of forming paper board from paper pulp which comprises suckingr a layer of pulp from stuff water on to a sieve and couching the formed layer on to a flexible body by which such layer is also removed from the sieve to permit of the formation of a further layer thereon.

The invention also consists in apparatus for forming paper board by the method according to the preceding paragraph comprising a platen having thereon a sieve spaced apart from the platen so that a layer of pulp may be deposited thereon by suction and a second platen having a surface formed by a exible body and controlled by hydraulic ram and cylinder or otherwise, so that the fiexible body may be moved into contact with the formed layer on the sieve to couch the same and remove it from the sieve preparatory to the formation of a further layer thereon.

Further features of the invention will be apparent from the description given hereafter.

The accompanying drawing illustrates in sectional elevation one convenient form of apparaus in accordance with the invention.

In carrying my invention into effect in one convenient manner, I may form my improved apparatus With any suitable bedplate a foundation or supporting framework, upon pillars b or slides forming part of which I mount upper and lower platens, either or both of which may be movable for the purpose of causing the same to approach or recede from one another as may be necessary during the operation of forming paper boards.

In the particular construction shown, the upper platen may carry or comprise a flanged ring c of any desired shape in plan within which I mount a metal or other backing or support d spaced slightly apart from which is a sieve plate e and co-operating with this upper fixed platen I arrange a lower movable platen f adapted to be controlled by hydraulic ram and cylinder of suitable form so that it may be made to approach or recede from the upper platen.

The lower platen f is preferably formed with a peripheral annulus f into which the stu water is admitted for suction through the upper sieve so as to deposit thereon a layer of felted fibrous material, the thickness of which is obviously limited by the capacity of the layer to pass further liquid therethrough. 0

Within the part of the lower platen surrounded by the above annulus, I arrange a metal or other plate g having a rubber or rubber and felt or other like flexible surface h constituting a exible body adapted to be` pressed into contact with the sieve by operation of the hydraulic ram so as to couch the layer of pulp upon the sieve and remove the same on reverse movement of the hydraulic ram so that such layer z is thus transferred from the sieve to the flexible body whereupon a further layer may be deposited upon the sieve and subsequently couched upon the exible body and so on until a board or plate of the desired thickness has thus been transferred to the flexible body.

Behind the backing plate of this flexible body I dispose an inflatable bag or series of bags 1c arranged in recesses or otherwise located so that during normal operation of the hydraulic ram the bag or bags will not be compressed and the couching pressure is that which is thus due to the hydraulic pressure and which will be determined by the relative areas of the sieve and hydraulic cylinder respectively.

When, however, the last layer has been formed upon the sieve, the ram is moved so that the layers upon the exible body are brought into contact with the layer upon the sieve and the platens locked in position by suitable means (such as the pivoted locking members l), whereupon high pressure water or air is admitted to the inflatable bag or bags and the pressure is maintained for suiiicient time to consolidate the material and the layers together and to express as much as possible of the remaining water therefrom.

When the board or plate is sufficiently pressed, the pressure is released, the head unlocked and the platens separated to permit of removal of the nished board.

By the invention, I am able to produce plain paper boards of any desired thickness or by suitable shaping of the parts the boards may be embossed or corrugated or otherwise similarly formed.

By a suitable construction of machine I may form any number of the boards simultaneously.

It will be understood that the apparatus is provided with all necessary valves and regulating means, the operations of which may be timed and controlled in proper sequence by hand or automatically as for example in the manner described in the specification of application Serial No. 723,774 or in any other suitable manner.

*pulp layer upon the sieve. 'i

Having now described Y'my invention, what I claim as new anddesire to secure by Letters Patent is:-Y

\ l. Apperatusfor forming palier board by the paper making process comprising two platens movable relatively to one another and enelosing a. space to which stuff water is admitted. a sieve carried by one of the platens on t which a layer of pulp is deposited by suction, and a member carried by the other platen and having a exible surface adapted to be pressed into contact with the sieve to couch the layer of pulp thereon and transfer'the same from the sieve to the ilexible surface preparatory to the formation of a further 2. Apparatuslfor forming paper board by the paper making process having the combination cclaim 1 and means for locking the platens together when the board reaches the desired thiol:-Y ness and means for applyingf high pressure to i consolidate the board.

3. Apparatus for forming paper board by the paper-making process according to claim 1 characterized by the member having a flexible surface being mgvable in relation to the platen carrying the same and combined with inflatable means arranged to apply high pressure to movable member for the purpose of consolidating the board. EWEE ROSS SMITH. 

